1. Field of the Invention
The present invention relates to a reproducing apparatus and a method of an optical information recording medium for reproducing recorded information from the optical information recording medium in which the information is recorded on a disc-like medium with pits or the like, or a recording/reproducing apparatus being further possible to record information (hereinafter, it is called only by a recording/reproducing apparatus of an optical information medium), and in particular to an optical disc apparatus for performing the recording/reproducing of information on a medium of so-called a land-groove method.
2. Description of Related Art
Conventionally, various kinds or types of recording/reproducing apparatuses for optical information recording medium are already known and are in practical use, which read out the recorded information optically for reproduction thereof, from an optical information recording medium on which the information is recorded by forming pits with use of so-called a phase-change or the like on a disc-like optical recording medium. In particular, recent years, an optical recording medium, being able to record a large amount of information with high density in the recorded information, was proposed and attracting attentions, for example that called by a VD (digital video disc), and also a reproducing apparatus for reading out the information thereof, a part thereof, is already available on a market.
However, with such the high density recording medium including such as the DVD, etc., for the purpose of increasing the density in information recorded on the disc-like medium, a laser beam is applied to, being shorter in the wavelength than that used in previous, and further for the purpose of increasing the density in track pitch, a concave portion and a convex portion, being called groove area and land area respectively, are formed on the recording surface of the medium, so as to record the information in those areas. More, the land area or the groove area appears alternatively for each round, following a tacking operation by an optical pickup as an optically reproducing means. Also, as such the high density recording mediums, there are proposed various kinds of recording mediums, such as a recording medium which enables only reproduction of the information recorded, a recording medium which enables recording of only one-time, and further a recording medium which enables a plurality of times of recordings, etc. However, among those kinds of the recording mediums, characteristics or properties are different to one another, in particular in reflectivity or reflection factor thereof.
On a while, in a recording/reproducing apparatus of optical recording medium for reproducing the recorded information from such the high density recording medium, in which such the concave and the convex portions called as the land area and the groove area are formed, conventionally, a control is applied for controlling a focus position of the optical reproducing means thereof, in which the focus position for the land area and the focus position for the groove area are exchanged alternatively, for each round, in synchronism with an address signal recorded in an area defined between the land area and the groove area, namely called by a pit address, in advance.
Also, from conventionally, a high reliability of the information is achieved by conducting a so-called verify control, i.e., it is confirmed whether the recorded data can be reproduced correctly or not when recording information onto the optical recording medium.
However, with such the high density recording medium, for correctly reproducing the information recorded with high density or for recording it, there are necessitated initialization of various devices constructing the optical disc apparatus and control of operations for performing the recording/reproducing smoothly. In particular, with such the apparatus necessitating such the accurate control, many confirmations must be performed from a turning ON of a power supply up to a ready condition, i.e., the information can be read out from the optical disc correctly.
For example, in the optical disc apparatus, it must be decided whether the optical disc is inserted or not, first, under the condition where the power supply is turned ON, and further, whether the optical disc is a CD-ROM, a DVD-ROM or a DVD-RAM. Setting condition varies for those different optical discs, therefore it is very important.
Also for the high density recording medium mentioned above, for the purpose of reproducing the information recorded with high density, it is necessary to control an optical pickup as the optical reproducing means, in particular the focus position of the focus lens, with higher accuracy. Ordinarily, with the recording/reproducing apparatus for optical information medium, the focus position is adjusted so as to be controlled at an appropriate position obtained in advance when being shipped, however, it is important to control the focus position at an appropriate position in conformity with, for example, the kind and/or condition of the recording medium, and further an environment of use of the apparatus, including the temperature and so on. For that purpose, modifying the focus position to an ideal position is conducted on a basis of the recorded data which is reproduced actually with the apparatus by applying a control, such as a learning control, etc.
Further than the above, the confirmation must be made on many operations, including such as presence of a cassette, selection of the optical pickup, adjustment of tracking, adjustment of writing in, etc.